1. Field
The present invention relates to an antistatic hard coat layer-forming composition, an optical film, a production method of an optical film, a polarizing plate, and an image display device.
2. Description of the Related Art
In an image display device such as a cathode ray tube display device (CRT), a plasma display panel (PDP), an electroluminescent display (ELD), a vacuum fluorescent display (VFD), a field emission display (FED) and a liquid crystal display device (LCD), a transparent optical film having an antistatic property and a hard coat property is suitably provided to prevent reduction in visibility due to scratching of the display surface or attachment of dusts or the like.
In order to obtain an optical film having an antistatic property and a hard coat property, it is known to form an antistatic hard coat layer by using a composition containing an ion-conducting compound as an antistatic agent, such as quaternary ammonium salt group-containing polymer, and a polyfunctional monomer functioning to a binder (see, for example, JP-A-2009-263567 (the term “JP-A” as used herein means an “unexamined published Japanese patent application”), JP-A-2005-316428, JP-A-2009-86660 and JP-A-2003-39619).
Here, due to bad compatibility between the ion-conducting compound and the polyfunctional monomer, the ion-conducting compound is aggregated and unless the ion-conducting compound is added in a large amount, a sufficient antistatic property is not obtained. However, when the ion-conducting compound is added in a large amount, an adequate hard coat property may not be obtained.
In order to solve this problem, for example, WO 03/055950 describes an optical film having an antistatic hard coat layer formed of a composition containing a quaternary ammonium salt group-containing polymer, a polyfunctional monomer and, as a compatibilizer, 2-hydroxyethyl acrylate.